Thermionic tube and anode plate therefor



Oct. 23, 1945. M. BAREISS 2,387,238 THERMION IC TUBE AND ANODE PLATE THEREFOR Filed Sept. 5, 1943 INVENTOR 1 MAX.BAHE/SLS ATTORNEYS Patented Oct. 23, 1945 UNITED STATES ATENT OFFICE THERMIONIC TUBE AND ANODE PLATE THEREFOR Max Bareiss, Livingston, N. J assignor to Tung- Sol Lamp Works 1110., Newark, 'N. J a corporation of Delaware This invention relates to'thermionic devices, and particularly to structures including a novel and improved anode plate therefor and method of making the same.

This invention relates more particularly to the manufacture of anode plate structures for transmitting tubes in which the plates are generally cylindricallyshaped and closed at one end. Such plates have heretofore been made of tantalum whose-properties permit of deep drawing and spot welding. :A typical plate 'of this character embodies a cylindrical side wall and a deep drawn thimble closing the end of the cylindrical structure, the parts being fastened by spot welding.

Refractory metal, such as molybdenum, is abundant and relatively inexpensive and is suitable for use in the manufacture of anode plates and particularly so if provided with zirconium coatings, which improve the thermal radiation and due to their getter effect, permit reasonable time of exhaust. Molybdenum, however, cannot be deep drawn and it is very difficult to spot weld it to itself.

An object of the invention is a novel and improved anode plate structure formed of a refractory metal like molybdenum and a novel and improved method of forming the same.

Further objects of the invention will hereinafter appear.

For a better understanding of the invention reference may be had to the accompanying draw-- ing forming a partof this application, wherein Fig. 1 is a thermionic device embodying the invention;

Fig. 2 is a plan view illustrating one of the blanks used in the formation of the anode plate;

Figs. 3 to 6, inclusive, are perspective views illustrating steps in the formation and assembly of the blanks into a completed anode;

Fig. 7 is a plan view of a completed anode;

Fig. 8 is a section-along the line 8-8 of Fig. 6; and

Fig. 9 is a plan view of blanks utilized in following a slightly different method of forming and assembling the anode.

Referring to the drawing, I'have illustrated my invention as embodied in a transmitting tube I having filament support wires 2 mounted in a press 3, a grid support 4 and an anode support 5. The grid support 4 is fused into the side wall of the envelope of the tube and the anode support is fused into the end of the envelope in accordance with conventional structures. These supports may be of tungsten.

My novel and improved anode plate A comprises a cylindrical body 6 having a closed domelike structure 1, a side fin or wing 8 extending throughout the length of the cylinder 6 and projecting upwardly beyond the level of the topmost part or apex of the dome 1, and two shorter fins or wings 9 and l 0 extending up to the base of the dome 1, these members 8, 9 and it being equally spaced circumferentially about the anode from each other. The elongated fin 8 is fastened to the support 5 by means of the angularly disposed part 5' formed integrally with or welded to the support 5.

The dome '1 is formed from a multiplicity of narrow strips formed from the blanks from which edges, these cuts extending down a substantial distance as indicated in Fig. 2, and leaving on the sides uncut portions. This results in the formation of a series of narrow sheared pieces or strips l3 integrally formed with the body of the blank. These shear-like cutsand strips may be formed simultaneously with the forming of the blank if desired or they may be formed as a separate step in the formation of the blank. The

blank is also formed with H cuts l4 near the sides thereof which cuts are disposed below the level of the lower ends of the cuts l2. In the particular embodiment shown there are two of these H cutsl l on either side of the blank. These cuts leave pairs of tongues l5 which are utilized as described below for stitching the blanks together to form a rigid structure.

The blank thus formed embodies two side panels B and a central panel C, the central panel C being bounded by the dotted lines shown which form continuations of the outside shearing cuts [2. The pieces or strips l3 form a part of the panel C. With the blank thus formed, the panel C is formed into the one-third part (120 arc) of a cylinder while the panels B are disposed at right angles to tangents to the circles of the cylinder. The blank thus formed is illustrated in Fig. 3.

" Three of the blanks thus formed are assembled ting panel and crimped about the tongues I5 thereof, as indicated in Figs. 6 and 8. The three blank forms of Fig. 3 are thus firmly fastened together to form the cylinder 6 with the wings or fins 8, 9, I projecting outwardly therefrom and formed of adjacent abutting panels B.

After the three parts or forms are thus stitched toegther, the sheared pieces or strips 13 are twisted and. bent over a semi-spherical mandrel to form the dome-like shape I, the mandrel being omitted for convenience in illustration. The outer ends of these narrow strips or pieces l3 overlap and pile up upon each other at the apex I of the dome to form a substantially closed end of the unit. The slitted openings provided between the adjacent overlapping strips assist in the ventilation while, as described, forming a substantial closure for the end of the cylindrical anode V arating operation may take place either before or after the dome I is formed. The fin or wing 8 is maintained intact throughout its length to serve as a support for the unit. To this end the upper end of the fin 8 is provided with a groove 16 within which groove is welded the part of the support wire, this part 5' being nickel, for example, which may be readily fastened to the molybdenum fin 8 by welding. The upper part 5 of the support wire is preferably tungsten. Fig. 6 shows the finished molybdenum anode, which is then ready for mounting in the transmitting tube 1.

The necessity for severing and removing the upper parts of the fins or wings 9 and I0 after the formation of the blanks (Fig. 3) may be obviated by initially forming three fiat blanks of the special forms illustrated in Fig. 9. Two of these blanks I! and I8 are identical except that they are right and left handed and the third blank is indicated at I9. The panels C are formed into cylindrical sections as indicated in Fig. 3 and the blanks are assembled so as to bring the severed panels B into mating engagement while the unsevered or elongated panels B of the forms II and I8 are brought into mating engagement. With the three blank here shown avoid the difiiculty of spot welding of molybdenum andthe like to itself for fastening.

I claim:

1. In a thermionic tube, an anode of cylindrical shape embodying a multiplicity of narrow strips formed integral with the body of the anode and bent over upon each other to form a dome-like closure.

2. In a thermionic tube, an anode of cylindrical shape embodying a multiplicity of narrow strips formed integral with the body of the anode and bent over upon each other to form a dome-like forms 11, I8 and I 9 thus assembled, the panels are stitched together by the tongues l5 previously formed in the blanks, as described above with respect to Figs. 5, 6 and 8. The strips l3 are then bent over on a mandrel to form the closed domelike end I as described above and the fin or wing 8 is formed with the groove Hi to facilitate welding of the support wire 5 to the fin.

This structure A may thus be readily formed out of refractory metals like molybdenum which is plentiful and functions efliciently as an anode. The dome structure and the zirconium coating applied to the anode improve the thermal radiation and the zirconium coating,.due to its getter effect, permits exhaust within a reasonable time. Moreover, the difliculties of drawing the metal are, by the structure herein shown, avoided, and likewise the structure and method of manufacture closure, said cylindrical body having projecting outwardly therefrom a plurality of fins, one of said fins extending up beyond the base of the dome and a support for the anode fastened thereto.

3. In a thermionic tube, an anode of cylindrical shape embodying a multiplicity of narrow strips formed integral with the body of the anode and bent over upon each other to form a dome-like closure, said cylindrical body having projecting outwardly therefrom a plurality of fins, one of said fins extending up beyond the base of the dome and a support for the anode fastened thereto, and the other of said fins stopping in the vicinity of the base of the dome.

4. In a thermionic tube, an anode of cylindrical shape embodying a multiplicity of narrow strips formed integral with the body of the anode and bent over upon each other to form a dome-like closure, said anode plate being formed of molybdenum and the like having coatings thereon which enhance the thermal radiation.

5. In a thermionic tube, an anode of cylindrical, sh'ape embodying a multiplicity of narrow strips formed integral with the body of the anode and bent over upon each other to form a domelike closure, said cylindrical body having projecting outwardly therefrom a plurality of fins, one of said fins extending up beyond the base of the dome and a support for anode fastened thereto, said anode plate being formed of molybdenum and the like having coatings thereon which en- V hance the thermal radiation.

6. In a thermionic tube, an anode of cylindrical shape embodying a multiplicity of narrow strips formed integral with the body'of the anode and bent over upon each other to form a domelike closure, said cylindrical body havin rojecting outwardly therefrom a plurality of fins, one of said fins extending up beyond the base of the dome and a support for the anode fastened thereto, and the other of said fins stopping in the vicinity of the base of the dome, said anode plate cal shape embodying a multiplicity of narrowstrips formed integral with the body of the anode and bent over upon each other to form a domelike closure, said cylindrical body having projecting outwardly therefrom'a plurality of fins, one of said fins extending up beyond the base of the dome and a support for the anode fastened thereto, said anode plate being formed of molybdenum and the like provided with a getter coating.

9. In a thermionic tube, an anode of cylindrical shape embodying a multiplicitiy of narrow strips formed integral with the body of the anode and bent over upon each other to form a domelike closure, said cylindrical body having projecting outwardly therefrom a plurality of fins, one of said fins extending up beyond the base of the dome and a support for anode fastened thereto, and the other of said fins stopping in the vicinity of the base of the dome, said anode plate being formed of molybdenum and the like provided with a getter coating.

10. In a thermionic tube, an anode of cylindrical shape embodying a multiplicity of narrow strips formed integral with the body of the anode and bent over upon each other to form a domelike closure, said anode being formed of molybdenum and the like and provided with a zirconium coating.

11. In a thermionic tube, an anode" of drical shape embodying a multiplicity of narrow strips formed integral with the body of the anode and bent over upon each other to form a domelike closure, said cylindrical body having projecting outwardly therefrom a plurality of longitudinally extending fins, one of said fins extending up beyond the base of the dome and a support for the anode fastened thereto, said anode being formed of molybdenum and the like and provided with a zirconium coating.

12. In a thermionic tube, an anode of cylindrical shape embodying a multiplicity of narrow strips formed integral with the body of the anode and bent over upon each other to form a domelike closure, said cylindrical body having project'- ing outwardly therefrom a plurality of fins, one of said fins extending up beyond the base of the dome and a support for the anode fastened thereto, and the other of said fins stopping in the vicinity of the base of the dome, said anode being formed of molybdenum and the like and provided with a zirconium coating.

-l3. An anode of closed shape for a thermionic tube having a substantially closed dome-like end and a fin projecting outwardly from the surface of said anode and projecting at one end beyond said dome-like end and a support for said anode fastened to the projecting end of said fin.

14. In a structure of the character set forth in claim 2 wherein the anode plate is formed of three equal cylindrical parts mated together with panels projecting therefrom stitched together to form three equally spaced fins.

15. The method of forming anode platesand the like for use in thermionic devices which comprises the steps of forming two or more blank forms which together form a cylinder with one end of the cylindrical portions of the blanks formed into narrow strips extending longitudinally of the cylinder and th'en bending said strips over a mandrel to form a dome-like closure for the end of the cylinder.

16. The method of making an anode plate for use in thermionic tubes comprising the steps of forming two or more blanks having cylindrical parts which together form a cylinder, forming one end of the cylindrical part of said blanks with a multiplicity of narrow strips extending longitudinally of the cylinder, forming longitudinal and equally spaced panels on the edges of aid blanks, assembling said blanks together to form a cylinder with the panels of adjacent blanks abutting against each other, fastening the abutting panels together to form a rigid structure and bending the strips inwardly about a cylin mandrel to form a dome-like closure for the cylinder.

17. Themethod of making an anode plate for use in thermionic tubes comprising the steps of forming two or more blanks having cylindrical parts which together form a cylinder, forming one end of the cylindrical part of said blanks with a multiplicity f narrow strips extending longitudinally of the cylinder, forming longitudinal and equally spaced panels on the edges of said blanks, assembling said blanks together to form a cylinder with the panels of adjacent blanks abutting against each other, fastening the abutting panels together to form a rigid structure and bending the strips inwardly about a mandrel to form a dome-like closure for the cylinder, with the strips overlapping and piling upon each other toward the apex of the dome.

18. The method of making an anode plate for a use in thermionic tubes comprising the steps of forming two or more blanks having cylindrical parts which together form a cylinder, forming one end of the cylindrical part of said blanks with a multiplicity of narrow strips extending longitudinally of the cylinder, forming longitudinal and equally spaced panels on the edges of said blanks, assembling said blanks together to form a cylinder with the panels of adjacent blanks abutting against each other, fastening the abutting panels together to form outwardly projecting fins and a rigid structure and bending the strips inwardly about a mandrel to form a dome-like closure for the cylinder, and forming one of said fins with means for attachment to a support.

19. The method of forming an anode plat which consists in forming two or more blanks with cylindrical parts which together form a cylinder with the parts having side panels co-extensive with the length of the parts with longitudinal slits formed at one end of the cylindrical part, and then assembling and fastening the parts together and. severing and removing the ends of certain of the panels.

20. The method of forming an anode plate which consists in forming three blanks having panels projectig from the sides thereof, the panels on one of said blanks being of the same length and the panels of each of the other two blanks being of unequal length, forming the parts of the blanks intermediate the panels into cylindrical shape, and then assembling the blanks together to form a cylindrical anode plate with the panels of adjacent blanks mating togeth'er to form fins projecting outwardly from the surface of the anode plate and the longer panels projecting at one end to form a means for attaching a support.

21. The method of forming an anode plate which consists in forming two or more blanks having panels projecting from the sides thereof, forming the parts of the blanks intermediate the panels into complementary parts of the walls of a closed structure, slitting the complementary parts at one end to form narrow strip and then assembling the blanks to form a closed structure with the side panels forming fins and the narrow strips being bent over upon each other to form a closed end.

22. An anode plate of closed shape for thermionic tubes embodying a mutiplicity of narrow strips formed integral with the body of the anode and bent over upon each other to form a closed end.

MAX BAREISS. 

